Leak stopper for condenser tubes



Nov. 11, 1941. s. PENNELLA 2,262,042

LEAK STOPPER FOR CONDENSER TUBES Filed Feb. 21, 1941 Fiq i fi arnual"Pnnalla INVE K A Tl'ORNEY Patented Nov. 11, 1941 UNITED STATES PATENTOFFICE" LEAK s'rorrsa roa CONDENSER TUBES SamnehRennella, East Orange,N. I. Application February 21, 1941, Serial No. 380,003

3 Claims.

This invention relates to condenser tubes, and more particularly to leakstopping inserts for insertion into a condenser tube for preventing Yleakage through openings formed in the tubes by corrosion or erosion.

The cooling water flowing through the tubes of a surface condensercauses failure of the inlet ends of the tubes, due to impingement,erosion and electro-chemical corrosion, resulting in the eating away andperforation of the tube, causing leakage. Such action has been found byexperience to be most severe in close proximity to the inlet end. of thetube. It has been the practice heretofore to replace such leaking tubesat a considerable expense both in cost of new tubes, cost of theoperation of re-tubing of the condenser, and also in the resultant-lossof tubes which have only ashort part of their entirelength renderedincapable of proper operation.

It is an object of the present invention to provide an insert orleak-stopping sleeve for insertion into the eaten away" end of the tubefor effectively sealing any leaks therein, consequently prolongingthe-life of the tube, as well as eliminating for a practical period oftime the necessity for re-tubing the condenser.

It is necessary, to stop such leaks and prevent further deterioration ofthe tubes, that the leak stopping insert or sleeve fit the interior ofthe tube in fluid tight engagement, and necessary also that the act offorcing the insert into the tube not disrupt or break the corroded tube.An object of the present invention is to provide a novel, practicalinsert which can be readily forced into a corroded tube withoutdisrupting or rupturing the tube structure, which will effectively stopall leaks in the tube, and one which will not impair the heat transferefiiciency of the condenser byadversely affecting the cooling water flowthrough the tubes.

More specificallyQthe present invention comprises a leak stopping insertof suflicient hardness and density to permit it to be accuratelymachined, yet one which will swell or expand when wetted or moistened,so as to tightly fit within the condenser tube and form a fluid tightengagement with the interior of the condenser tube. This fiber tube islined with a metal sleeve, preferably of the same metal as that which isemployed in the condenser tube. metal sleeve prevents internal expansionof the fiber sleeve and permits free unimpeded flow of cooling waterthrough the condenser tube.

With these and other objects in view, as may indicates a watercirculating tube of a surface invention consists of various features ofconstruction and combination of parts, which will be first described inconnection with the accompanying drawing, showing a leak-stopper forcondenser tubes of the preferred form embodying the invention, and thefeatures forming the invention will be specifically pointed out in theclaims.

In the drawing:

Figure .1 is a view, partly in section, of a condenser tube,illustrating the manner in which it is eaten away by erosion andcorrosion.

Figure 2 is a, longitudinal section through a condenser tube showing theimproved leak-stopping insert therein.

Figure 3 is a cross-section on the line 3-3 of Figure 2.

Figure 4 is a fragmentary longitudinal section through a modified formof the invention.

Referring more particularly to the drawing, l

condenser which has been attacked by both erosion and corrosion, causingan eating away of parts of the interior of the condenser tube, as shownat 2. Such eating away of the condenser tube eventually causes openingsor perforations, as indicated at 3, in the tube, resulting in leakage ofcirculating cooling water into the con-,- densing space of the condenserand pollution of the-condensate as well as decreasing the heat transfereificiency of the surface condenser.

This corrosion of the condenser tubes, it has been found, occurs at andadjacent to the inlet end of the tubes, resulting in the spoiling ofonly a short section of the entire length of the tube. However, it isthe practice, when the inlet ends of such tubes are eaten away, toremove the entire tube andreplace it with a new tube, incurringconsiderable expense occasioned by the purchase of new tubes, theremoval of the old tubes and the retubing of the condenser, as well asthe loss of the major portion of the corroded tubes. The presentinvention comprehends an insert which may be inserted into the condensertube to form an inner wall for the corroded portion of the tube and stopthe leakage of the circulating cooling water through the openings in thetube caused by the corrosion or erosion. When the tube is eaten away tosuch an extent that it is porous or has holes therethrough, the walls ofthe tube are necessarily weakened. To provide an effective stoppage ofthe leaks and to prevent further corrosion and erosion of the tube, itis necessary that the leak stopping inappear from the accompanyingspecification, the sert be in fluid tight engagement with the tube.

If the leak stopping insert is of sufiicient size to form a fluid tightengagement with the inner wall of the tube, the driving of such insertinto the tube is quite apt to rupture the eaten away portion of thetube, resulting in the necessity of replacing the tube. The presentinvention provides an insert which will not only prevent rupturing ofthe eaten away or weakened portion of the tube, but will also form afirm,

secure, fluid tight connection with the tube, effectively preventing anyleakage.

The insert, generically indicated by the numeral It, comprises an outersleeve ll, formed of fibrous material of sufilcient hardness and densityto permit it to be accurately machined. It is turned so that its outerdiameter is slightly less than the inner diameter of the condenser tubeI. Thus it may be easily driven or forced into the condenser tubewithout undue strain upon the weakened tube portion. The fibrousmaterial is of such nature that when it is wetted or becomes moist itwill swell suificiently to form a firm, secure, fluid tight engagementwith the inner surface of the condenser tube l, eifective- 1y sealingoil any leakage of circulating water from the tube as well aseffectively preventing the leakage of any circulating cooling waterbetween the facing surfaces of the condenser tube and the leak stoppinginsert. The fibrous material sleeve is prevented from inward expansionby a metal sleeve 12, which is driven or forced tightly into theinterior of the fibrous sleeve ll, forming an inner metal wall for thereinforced portion of the condenser tube. The metal sleeve I2 ispreferably made of the same material as is the material of which thecondenser tube I is formed. The thickness of the leak stopping insert Igradually decreases as it approaches the outlet end of the insert, asshown at M in Figure 2 of the drawing, forming a slightly increasedoutlet which gradually merges intothe line of the interior bore ordiameter of the tube I so as to prevent the formation of eddies at theoutlet of the insert.

In Figure 4 a slightly modified construction of the invention is shownin which a second leak stopping tube or insert of larger diameter isemployed for securely holding the insert in a conleak inserts, a stopleak insert 22 of the same construction as shown in Figures 2 and 3 ofthe drawing is inserted into the condenser tube, and a second insert,shown at 28, is forced over-the outer surface of the insert 22 in theenlarged or belied end 2! of the tube 20. This second or larger insert28 comprises a sleeve 24 of the fibrous material, which has a metallining sleeve 25 therein. This metal lining sleeve 25 contacts thefibrous sleeve 26 of the insert 22 and is firmly held thereon in fluidtight engagement upon the expansion of the fibrous sleeve 28 due to itsbeing moistened or wetted. The outer fibrous sleeve 24 of the insert 23fits tightly against and in fluid tight engagement with the inner wallof the enlarged end ll of the tube 20.

It will be understood that the invention isnot to be limited to thespecific construction or arrangement of parts shown, but that they maybe widely modified within the invention defined by the claims.

What is claimed is:

1. Means for stopping leaks in a condenser tube perforated by corrosionor erosion comprising a tubular insert of a hard compact fibrousmaterial subject to swelling orexpansion when wetted, and a metal sleevewithin said fibrous tubular insert, said fibrous material swelling uponwetting to seal leaks in a tube.

2. Means for stopping leaks in a condenser tube perforated by corrosionor erosion comprising a tubular insert of hard compact fibrous materialsubject to swelling or expansion when wetted, and a metal sleeve withinsaid fibrous by its swelling action upon wetting, and means within saidtubular insert to restrain the tubular insert from swelling inwardly.

3. The combination with a condenser tube perforated by corrosion orerosion, of a tubular insert of hard compact fibrous material subject toswelling or expansion when wetted, inserted into said condenser tube andswelling upon wetting to seal the leaks in the tube.

SAMUEL PENNELLA.

CERTIFICATE OF ccnmzcno ng- Patent No. 2,262,0h2. November 11, 19m.

SAMUEL PENNELLA It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction asfollows: Page 2, second column, line 58, claim 2, strike out the come.and words and a metal sleeve within saidfibrous" and insert instead--end serving to seal such leaks in "the tube; and that the said LettersPatent should be read with this correction therein that the sage mayccnforn to the recorder the casein the Patent Office.

Signed and sealed. this 501:1; a er Play, A. D. 191 1;.

Leslie Frazer (Seal) Acting Ccmmissicner of Patents.

